Adhesive device



Jan. 12, 1965 B. BORISOF ADHESIVE DEVICE Filed July 22, 1963 FIEB ,FlE.EFIE 5.7

[7? 2/2 72 for r Ber/Ia I'd Borzlsaf p ffbrzze ys 3,165,23 Patented Jan.12, 1965 3,165,283 ADHESIVE DEVICE Bernard Borisof, Chicago, 11].,assignor to Lectro-Stik Company, Chicago, Ill., a partnership Filed July22, 1963, Ser. No. 296,612 7 Claims. (Cl. 24829) This invention relatesto a removable and re-usable adhesive fastening device for holdingposters, bulletins, decorations, and other similar articles on windows,walls, or any other surfaces.

It is customary to mount posters and signs with pressure sensitveadhesive tape. This requires two hands to tear off pieces of the tape,making it awkward for the user who is meanwhile attempting to hold theposter in position. If placed on the poster in advance, the pieces oftape often fold over and stick to themselves. Often, such tapeundesirably comes loose from cold or wet surfaces due to the differencein expansion of tape and surface on which it is mounted. Otherwise, ifit does adhere to a surface for a long time, the tape is difficult toremove, requires scraping with a-razor. In general, such tape cannot beremoved from paper articles without tearing them. For mounting salesdescriptions on merchandise,

' tape is unsightly and detracts from the appearance. Pressure sensitivetape is generally not re-usable, and it cost tends to be high,especially in school rooms where hundreds of items are hung on walls,windows and blackboard.

Tacks, thumbtacks, and staples are also used for supporting signs,posters, and similar notices. These fasteners have drawbacks in thatthey leave holes; and cannot be used at all on hard surfaces like glass,blackboards, or metal. Thumbtacks require soft bulletin boards, and area hazard when dropped. Tacks and staples require tools to install andtools for removal. These fasteners require too much effort for puttingup temporary memos in home or ofiice.

The present invention aims to overcome the above disadvantages byproviding a new and better fastening device for holding posters, signs,bulletins, memos pictures, decorations, calendars, and other articles onwalls, windows, or other surfaces.

It is an object of the invention to provide afastening device which maybe readily placed in position, using only one hand, only finger-tippressure, and requiring no tools.

Another object is to provide a fastener which will hold on glass, wood,metal, paper, paint, cloth, or any other surface, whether hard or soft,or rough or smooth.

Another object is to provide a fastener which will adhere indefinitelyto the surface to which it is applied regardless of ordinary temperaturechanges or the presence of moisture.

Another object is to provide a fastener which may be removed readilywith finger-tips and does not mar the surfaces to which it has beenattached.

Another object is to provide a fastener which is reusable hundreds oftimes.

A further object is to-provide a fastener whose initial cost isextremely low and which is neat in appearance.

, Other objects, features'and advantages of the invention will becomeapparent as the description proceeds.

FIG. 1 is an elevation showing a preferred embodiment of my invention;

- FIG. 2 is a plan view thereof;

FIG. 3 is an elevation taken along line 3-3 of FIG. 2;

FIG. 4 is an elevation showing an application of the invention;

FIG. 4a is a side end view of FIG. 4;

FIG. 5 is a perspective view showing a modification;

FIG. 6 is an end view of a further modification;

FIG. 7 is a side elevation of FIG. 6; and

FIG. 8 is a section taken along line 88 of FIG. 6.

With reference now to FIGS. 1 and 2, the adhesive device 10 comprises acup 11 and a body 12 of tacky plastic material disposed within the cupand adhered to the inside of the cup. The physical characteristics ofthe body of material 12 are similar to that which is associated with theterm mastic, which term is used herein to designate the cup.

The cup 11 is preferably a molded part of synthetic resin, but it may beformed of any suitable constraining material such as metal, wood, orheavy paper which adheres to the mastic.

The mastic consists essentially of a base material such as amicrocrystalline wax having. a melting point of 165 F., or apolyisobutylene ofa suitable degree of hardness, or any other adhesivematerial which retains its shape at ordinary temperatures, ispressure-sensitive adhesive, pressure deformable, non-resilient andpliable, non-volatile and non-setting, and which retains theseproperties upon removal and reapplication to a selected surface.

A preferred example is microcrystalline wax of a melting point of 165F., ASTM needle penetration of 23 at 77 F., and oil content of 5%.

Other examples are as follows:

' 7 Parts Microcrystalline wax, M.P. 165 100 Terpene resin (Piccolyte)30 The terpene resin adds tackiness, and the proportion can be variedthrough the range of from 10 parts to 70 parts per hundred parts ofmicrocrystalline wax base. Instead of terpene resin, other substancescanbe substituted in the same proportions, such as cumar resin, butylrubber, or natural rubber.

Parts Polyisobutylene (10,000 mol. wt.) 50 Polyisobutylene (80,000 mol.wt.) 50 Terpene resin 25 Polyethylene resin 5 The proportions of thetackifying agent, such as terpene resin or the other substancesmentioned in Example 1 can vary from 10 to 50 parts.

The polyethylene resin increases the tensile strength; the proportionscan be varied, and the polyethylene is not 1 always necessary dependingupon the hardness and tensile strength of the polyisobutylene base.The-proportions of this additive can vary from zero up to 30 parts per100 parts of base. Polyvinyl resin may be substituted for polyethylenein the same proportions.

The polyisobutylene base in this instance is a half and half mixture ofhigh and low molecular weights representing relativelyhard andrelatively-soft substances respectively. The proportions of the mixturemay be varied within limits of 10% either way, or even greater if thevariations in the hardening'agents are modified correspondingly. In thealternative, a polybutylene of medium molecular weight such as 45,000may be substituted for the mixture.

Fillers can be used in any of the above examples,

= I such as wood fibers, cotton linters, clay, Zinc oxide or thesurface.

iii. a

The operation is as follows: The poster 14 is placed in the desiredposition against the wall. Then the device is positioned so that itoverlaps the edge of the poster 14, and the cup 11 is pressed so thatthe mastic 12 adheres to both the wall and the poster.

The device lends itself readily'to this method of application. for handyuse. The device is positioned with one hand and finger tip pressurecompletes the fastening. The whole process takes about a second and issurprisingly fast compared to other adhesive fastening methods.

Since the mastic retains its shape and is non-free flowing, in order toeffect a permanent bond not subject to creep and failure, unit pressureinvolved in deforming the material is relatively high. Therefore, toafford ease of application of the device with one hand, it is desirablethat A number of the devices may be carried in a pocket" such as bits ofpaper, may bekneaded into itto buildup its volume for furthergreatlycontinued use. I

Permanently pliable adhesive mastics in lump form hav notheretofore beenconsidered suitable for use as adhesive devices because they tend toflow out of the pores of the bonded surface; also they will stretch andfail in tension.

Use of permanently tacky adhesives has been limited to thin films oncellophane tape. In thick adhesive applications, mastics have beencompounded with solvents or vulcanizing agents which cause the.materialto set and A harden so as to avoid cold flow, and thus is notreusable.

the area of surface 16 be less than two square inches, and

preferably a quarter of a square inch.

Whenthe device makes its first contact with a surface, the workableportion ld yields readily and the tacky adhesive surface conforms itselfto the mounting surface. The workable portion 13 may flow laterallyuntil the ,Width of the gap between the edge of the cup and the wall 15becomes small enough to offer suflicient resistance to the lateral flowof the .viscous material as to create a condition of equilibriumrepresenting a substantial fluid pressure within the cup 11. Thisresults in a good bond which extends throughout an area equal to thecross sectional area of the cup. The increase of pressure is alsobelieved to increase the tensile strength of the mastic 12 at pointsnear the surface 16, somewhat analogous to workhardening.

The adhesive device canbe removed and reused. Unlike adhesive tapes,which must be peeled for removal and thus tear paper articles, thisdevice may be twisted for removal. The twisting motion produces asliding action at the interface of the masticand the surface to which itis adhered, readily releasing its bond, and leaving the surfacesunmarred. I r

It is desirable that the back of the cup be wider than its diameter atthe opening to afford a better grip. In a preferred embodiment, thedevice has a knurled flange 17 tween the mastic portion 12 and the cup11, so that when the device is removed from a surface to which it hasbeen attached the mastic will be retained in the cup, and will not beleft on the surface. The area of adhesion within the cup exceeds area 16by the area of the side walls of the cup, thus providing for greateradhesion of the mastic inside the cup than at surface 16. This internaladhesion is further enhanced by the packing of the mastic between theside walls. This internal packing and adhesion can be further increasedby providing undercuts in the Walls of the cup and by ribs, projections,and other irregularities inside the cup.

In orderto insure clean removal of the device and prevent ruptureof themastic during removal, and also to insure stability during application,the total axial length of the device is not greater than its leastdiameter. Preferably the axial extension of the workable portion is madeshort enough, with respect to the consistency of the mastic, so that itwill not break during removal.

When the device is removed, the user can reform the workable portion 13,and thus obtain a new adhesive If the workable portion 13 loses itsadhesiveness through accumulation of dust or other foreign particlesafter being used many times, the mastic may be removed with afingernail, kneaded, and replaced in the cup, thus presentingnewadhesive surfaces. If the quantity of mastic becomes depleted after manyuses, a filler,

In the present invention, the combination of the cup 11, theper'manently'pliable mastic 12 and the projecting workable portion 13produces unexpected results:

(1) The combination produces ;a stronger and more uniform bond than apiece of mastic alone. Apparently the cup serves as a hydraulic vessel,distributes the pressure throughout the mastic, and thus bonds uniformlyover. the entire joint area. v

(2") It provides a stronger adhesive structure than a piece of masticalone, because (a) the cup brings the load line close to the plane ofthe bond, reduces the peeling turning moment, and thus reduces tensionforces normal to the plane of. the bond; and because (b)the'cup'prevents the mastic from stretching and failing in tension'inthe direction of the load.

(3) Pressing the device into place is believed to have whereby themastic'would flow out of the pores of the surface to which it is bonded.

-(4) The workable'portion of the mastic affords at the initial moment ofapplication a desirable yield-ability in conforming to anyirregularities of the surface to which it isappliedQ Also the initialflow presents fresh, tacky or adhesive surfaces and thus overcomesfingerprints'which often destroy the adhesiveness of pressure sensitivematerials. j

(5) It requires a surprisingly small area to provide an adequate bond:much smaller, for example, than the smallest piece of adhesive tape thatcan be torn and handled with convenience.

(6)'The relatively largermass of adhesive as compared to ordinary thinadhesive films, provides resilience against rupture due to strain andshrinkage caused by temperature'changes. 7

('7) The combination provides a ready means for removal,and'particularly means for removal by twisting which is not available inother adhesive fasteners or in a piece of mastic alone; and thus permitsremoval without marring or tearing the surfaces to which it has beenbonded.

(8) The lateral flow of the workable portion 13 and, at-re-use, theobvious ,and natural act of reforming the extension, provides anautomatic renewal of adhesive surfaces.

Furthermore, because of the cup, fingers may be removed from the devicewithout sticking and weakening the joint. And the combination provides aneat and tidy appearance which is not usual in adhesive applications.

In FIGS. 6 to 8, a double cup 213 is provided having mastic 12 in eachend. The device 1 can be used at the four corners of a picture frame formounting same on a wall.

Although the invention has been described with reference to theembodiments herein, other shapes of cups, vessels, or receptacles andother types of attachment to the device could be used without departingfrom the spirit of the invention so long as a cup and a yieldable adhesive mastic filling the cup and an extension of the mastic from the cupare combined.

From the foregoing disclosure it will be apparent that the presentinvention provides an adhesive fastener that is inexpensive, strong,neat and compact, most simple to apply and remove, applicable to hard orsoft or rough or smooth surfaces, non-destructive, and re-usable almostindefinitely.

I claim:

1. An adhesive fastening device for securing articles to vertical andother surfaces comprising a cup-shaped member, a homogeneous body oftacky pliable material disposed within said cup-shaped member and havinga volume greater than the capacity of said cup-shaped member, thatportion of said body which projects from said cup-shaped memberconstituting a workable portion pro viding a tacky, pressure sensitivesurface at room temperature for causing adhesion between said fasteningdevice and a vertical surface.

2. An adhesive fastening device as claimed in claim 1 in which saidcup-shaped member comprises a cylindrical member closed at one end andhaving a radially extending knurled flange projecting from thecylindrical wallthereof at the closed end for manipulative purposes.

3. An adhesive fastening device for securing articles to verticalsurfaces comprising a cup-shaped member, a body of tacky pliablematerial disposed within said cupshaped member and having a volumegreater than the capacity of said cup-shaped member, that portion ofsaid body which projects from said cup-shaped member constituting aworkable portion providing a tacky surface for causing adhesion betweensaid fastening device and a vertical surface, said body of tacky pliablematerial consisting essentially of a base substance selected from thegroup consisting of microcrystalline wax and polyisobutylene.

4. An adhesive fastening device as claimed in claim 3 in which said basesubstance includes a tackifying substance selected from the groupconsisting of terpene resin, cumar resin, butyl rubber and naturalrubber in the amount of from ten to seventy percent by weight of saidbase substance.

5. An adhesive fastening device as claimed in claim 1 in which saidcup-shaped member includes mechanical fastening means attached thereto.

6. An adhesive fastening device as claimed in claim 1 in which saidcup-shaped member includes a hook having a flexible shank connected to awall of said cup-shaped member and extending in a direction generallyperpendicular to the axis of said cup-shaped member.

7. An adhesive fastening device for securing articles to a verticalsurface comprising a cylindrical member open at both ends and having aninternal wall providing two oppositely and outwardly facing cup-likerecesses, a homogeneous body of tacky pliable material disposed withineach of said recesses and having a volume greater than the capacity ofsaid recesses, that portion of said body which projects from said recessconstituting a workable portion providing a tacky, pressure sensitivesurface at room temperature for causing adhesion between said fasteningdevice and a Vertical wall surface on the one hand, and between saidfastening device and an article to be supported thereby on the otherhand.

References Cited by the Examiner UNITED STATES PATENTS 1,5 60,029 11/25Erickson 248-205 2,421,253 5/47 Fleischner 248--117 2,492,411 12/49Barnes 248205 2,549,766 4/51 Benson '24829 CLAUDE A. LE ROY, PrimaryExaminer.

1. AN ADHESIVE FASTENING DEVICE FOR SECURING ARTICLES TO VERTICAL ANDOTHER SURFACES COMPRISING A CUP-SHAPED MEMBER, A HOMOGENEOUS BODY OFTACKY PLICABLE MATERIAL DISPOSED WITHIN SAID CUP-SHAPED MEMBER ANDHAVING A VOLUME GREATER THAN THE CAPACITY OF SAID CUP-SHAPED MEMBER,THAT PORTION OF SAID BODY WHICH PROJECTS FROM SAID CUP-SHAPED MEMBERCONSTITUTING A WORKABLE PROTION PROVIDING A TACKY, PRESSURE SENSITIVESURFACE AT ROOM TEMPERATURE FOR CAUSING ADHESION BETWEEN SAID FASTENINGDEVICE AND A VERTICAL SURFACE.